1. Field of the Invention
The present invention relates to a pendent fire protection sprinkler with a drop-down deflector. The present invention further relates to concealed pendent sprinklers for residential applications. The present invention relates to horizontal sidewall fire protection sprinklers, including those having a deflector with a rearwardly positioned horizontal shelf, which reduces the overall length of the sprinkler to provide a low-profile configuration. Such sprinklers may also be mounted in a supporting cup having a raised platform, with an escutcheon and cover, to provide a concealed configuration with improved sensitivity.
2. Related Art
Fire protection sprinklers conventionally are connected to a conduit to receive pressurized fire-extinguishing fluid, such as water. A typical sprinkler has a base with a threaded portion for connection to the conduit and an output orifice to output the fluid to provide fire control and/or suppression. The output orifice is sealed by a seal cap, which is held in place by a release mechanism. The release mechanism is designed to release the cap under predetermined conditions, thereby initiating the flow of fire-extinguishing fluid. A typical release mechanism includes a thermally-responsive element, e.g., a frangible bulb or a fusible link, and may include a latching mechanism.
Fire protection sprinklers may be mounted on a fluid conduit running along a ceiling and may either depend downward from the conduit, which is referred to as a “pendent” configuration, or may extend upward, which is referred to as an “upright” configuration. Alternatively, a sprinkler may be mounted on a wall, a certain distance below the ceiling, which is referred to as a “horizontal sidewall” configuration. Horizontal sidewall sprinklers have an output orifice that is oriented so that the fluid is output horizontally and sprays onto an area to be protected in front of the sprinkler. The area to be protected may extend across an entire room, in which case the relevant fire protection standards, e.g., Underwriters' Laboratories® Standard 1626, require the fluid flow to reach a particular height on the four walls surrounding the coverage area, among other requirements. Horizontal sidewall sprinklers are particularly useful in applications in which overhead piping is not easily installed, e.g., in residential applications.
Certain conventional sprinklers have a pair of arms that extend from a base, with the arms connecting at a hub. The hub is spaced apart from the output orifice of the base and is aligned with a longitudinal axis thereof. The hub may have a set-screw configured to apply a force to the thermally-responsive element and latching mechanism to maintain the seal cap in a position in which it seals the output orifice. A deflector is commonly provided, and may be mounted on the hub, transverse to the output orifice, to provide dispersion of the output fluid.
Other sprinklers have a deflector that is attached by a pair of arms that extend from the base of the sprinkler, but do not meet at a hub. In such sprinklers, the thermally-responsive element holds the seal cap in place without being held in compression by a hub. For example, U.S. Pat. No. 4,976,320 shows a sprinkler having a deflector attached to the body with arms that do not meet at a hub. The arms extend from the sprinkler body, and a drop-down deflector is attached to the sprinkler via two guide pins, which are installed in holes in a bent portion at the bottom of each arm. U.S. Pat. No. 5,664,630 shows another example of a sprinkler with a drop-down deflector.
U.S. Pat. No. 6,374,919 shows a horizontal sidewall sprinkler having a deflector with a horizontal shelf. The forwardly-extended portion of the shelf (approximately 0.6 inch) is greater than half the total length (approximately 1.0 inch) thereof. The sprinkler is mounted in a cup with a cover. The cup is mounted in a cavity in the wall such that the flange of the cup is flush with the wall surface. A cover is mounted on the flange so as to leave a gap therebetween to allow air flow to enter.
Technical bulletin “Series LFII Residential Horizontal Sidewall Sprinklers 4.2 K-factor” (Tyco Fire Products, Lansdale, Pa., April 2004) shows a horizontal sidewall sprinkler having a deflector with a horizontal shelf. The shelf is perpendicular to the frame arms and is approximately 0.7 inch in length, as measured from front edge to back edge near the center (the front edge faces away from the output orifice). The shelf appears to extend at a slightly upward angle with respect to the horizontal axis and has a protrusion in the center of the forward edge. The shelf extends approximately 0.43 inch beyond the major vertical surface of the deflector (i.e., the surface transverse to the fluid flow). Thus, the forwardly-extended portion of the shelf is approximately 61% of the total length thereof.
Technical bulletin “Series TY-L-5.6 K-factor Horizontal Sidewall Sprinklers, Standard Response, Standard Coverage” (Tyco Fire Products, Lansdale, Pa., January 2003) shows a horizontal sidewall sprinkler having a deflector with a horizontal shelf. The shelf is parallel to the frame arms and is approximately 0.66 inch in length, as measured from front edge to back edge near the center (the front edge facing away from the output orifice). The shelf extends approximately 0.37 inch beyond the major vertical surface of the deflector (i.e., the surface transverse to the fluid flow). Thus, the forwardly-extended portion of the shelf is approximately 56% of the total length thereof.
Technical bulletin “Model CHEC-8.0 K-factor Concealed Horizontal Extended Coverage Quick Response Light Hazard, Sidewall Sprinklers” (Tyco Fire Products, Lansdale, Pa., April 2004) shows a horizontal sidewall sprinkler having a deflector with a horizontal shelf. The shelf is perpendicular to the frame arms and is approximately 0.880 inch in length, as measured from front edge to back edge near the center (the front edge facing away from the output orifice). The shelf has a protrusion in the center of the forward edge. The shelf extends approximately 0.56 inch beyond the major vertical surface of the deflector (i.e., the surface transverse to the fluid flow). Thus, the forwardly-extended portion of the shelf is approximately 63.6% of the total length thereof. This document also shows the sprinkler mounted in a support cup assembly with a cover. The sprinkler is positioned in the support cup such that a frangible glass bulb is completely enclosed within the support cup and does not extend beyond the wall surface (i.e., the “retainer flange mounting surface”). The hub at which the frame arms meet is positioned so that a portion of the hub falls within the gap between the flange and the cover (i.e., within the “preset gap).
Some conventional horizontal sidewall sprinklers are installed in such a manner that their structure is visible, which is not aesthetically pleasing. Moreover, the sprinkler's extending structure tends to invite improper use of the sprinkler, for example to hang clothing or other items. Such improper use is undesirable, as it may render the sprinkler inoperable or cause unintended activation. Some conventional horizontal sidewall sprinklers are mounted in a support cup with a cover, such that the thermally-responsive element is positioned completely within the support cup. This arrangement tends to reduce air flow across the thermally-responsive element and correspondingly reduces the sensitivity of the sprinkler. Moreover, such configurations often include deflector shelves that extend significantly beyond the vertical surface of the deflector and require covers that extend further from the wall.